1. Field of the Invention
The present invention relates to an electronic stringed instrument, a musical sound generation method and a storage medium.
2. Related Art
An input control device is conventionally known for extracting pitch of an input waveform signal to instruct to generate a musical sound corresponding to the extracted pitch. As this type of a device, the technique has been disclosed in, for example, Japanese Unexamined Patent Application Publication No. S63-136088 for detecting a waveform zero-cross period immediately after detection of a maximum value of an input waveform signal and a waveform zero-cross period immediately after detection of a minimum value of the input waveform signal, and when both periods are approximately coincident with each other, instructing to generate a musical sound of pitch corresponding to the detected period, or detecting a maximum value detection period and a minimum value detection period of the input waveform signal, and when both periods are approximately coincident with each other, instructing to generate a musical sound of pitch corresponding to the detected period.
However, even using a method of this type, the strength of string-pressing with the left hand is not detected. Such a string-pressing force with the left hand varies in many stages in an actual guitar.
For example, a string is vibrated with correct musical pitch in the case of pressing a string to the extent of light press of a fret rather than fully pressing of the string down to a fingerboard. In a case where such a string-pressing force is increased, the string largely sinks down to the fingerboard together with a finger, thereby increasing tension of the string, resulting in a slight increase of the musical pitch. Using such a mechanism, a performer plays with vibrato.
Moreover, in a case where the string is in turn brought close to the fret with a press force of the finger to the extent that they are nearly pressing each other (actually not pressed), a phenomenon is then repeated that the string temporarily presses and moves away from the fret by string vibration. Thereby, both states occur where musical pitch is produced and where sound is completely muted with the finger. Such a sound sounds like a sound generated by mixing one half each of normal string vibration and a muted sound.
The string-pressing force further decreased from this state, and as the string moves completely away from the fret even though the finger is pressing the string, the volume of a normal sound of the string gets smaller, and contrarily, the muted sound gets greater.
Although the performer controls the strength of string-pressing with the left hand to subtly control timbre, a state of string-pressing with the left hand was not detected by a conventional method. Thus, there was no structure to generate the sound in this way, and subtle changes in timbre and pitch could not be reflected in accordance with the state of string-pressing.